The closely monitored Boston-area COVID wastewater tracker shows that virus data has been lower in recent weeks amid the BA.5 variant, which is an encouraging sign for the rest of summer.
The COVID sewage samples in the north of Boston region have now dropped 28% in the last few weeks, while the virus data in the south-of-the-city region has decreased 22% over the past month. Meanwhile, the highly contagious BA.5 omicron variant has become the dominant strain across the region.
The predictive wastewater data is an indicator for virus infection levels in the community.
“This is about what I’d been expecting,” said Matthew Fox, a Boston University School of Public Health epidemiologist. “Summer is usually quiet here in New England for COVID.
“We had some increase with the BA.4 and BA.5 but not too much and I expect this means the rest of the summer should be quiet,” he added. “Once we get back to schools opening and end of summer I expect things will pick up again, but hopefully not too strongly.”
The north of Boston seven-day average for COVID wastewater samples is now 580 copies per milliliter, down from the average of 804 copies in early July, according to Biobot Analytics’ test results from the Massachusetts Water Resources Authority’s pilot study to track wastewater at the Deer Island Treatment Plant.
The south of Boston seven-day average for COVID wastewater samples is now 575 copies per milliliter, a drop from the average of 739 copies last month.
The current wastewater data is still high, but it’s an improvement from the rates of more than 1,000 copies from early June, according to the Boston Public Health Commission.
“The improvement in our COVID-19 trends over the past two weeks is a welcomed sign, but we must remain vigilant, especially with the highly transmissible BA.5 variant making up a majority of cases in the region,” said Bisola Ojikutu, commissioner of Public Health and executive director of the Boston Public Health Commission.
“We’ve seen a consistent pattern of ups and downs for the past few months, but, overall, Boston’s metrics are at a medium risk level,” Ojikutu added. “The risk of transmission is still significant, and we all need to continue to take proper precautions to slow the spread of COVID-19 in our communities.”
The highly transmissible BA.5 variant, which accounts for 81.4% of new COVID cases in New England, has resulted in several instances of reinfection. The Boston Public Health Commission is urging people to get a booster shot, noting that the variant can evade immunity from the initial vaccine series and prior infection.